Unfair practise

I went to Studio 88 on the 25 Aug 2017 and made a lay-bye of sneakers which are R 1.200 and I placed a R 300 lay-bye. The balance is R 900 of which I couldn't afford so when I returned to the store on the 06 of Oct 2017 I wanted to make changes on the lay-bye but one the store assistants told me that whenever one makes a lay-bye there are terms and conditions regarding it and how unfortunate for me I wasn't told a thing about that and now I'm left in a limbo with a lay-bye I cant cancel nor change due to their lack of information which they were supposed to tell me before doing it. If I could get my money back or at least change it to something that I can afford I would be happy.